Saccocoma pectinata from Solnhofen

Originating in the famous, 150 million year old Jurassic Solnhofen Lithographic Limestone deposits near Bavaria, Germany, these pelagic (free-floating) comatulid crinoids are known as Saccocoma pectinata. They occur in seven separate layers deposited over some ½ million years, and are found dispersed among an amazing diversity of vertebrate and invertebrate organisms, the most famous of which is the dinosaur-age bird Archaeopteryx. As a member of subclass Articulata, Saccocoma are grouped among the only extant subclass of the class Crinoidea. They are differentiated from the remaining extinct subclasses by lack of an anal plate and the presence of entoneural system. The arms of all articulata are pinnulate in that they have alternating pinnules branching out along them to effectively increase the surface area for feeding, a characteristic clearly evident here. All fossils from the word-famous Solnhofen Lagerstatte are highly collectable. The site had the very special environment required to preserve the delicate floating crinoids. This fossil is entirely natural without staining; see other offerings for specimens stained to enhance the subtle contrast between fossil and limestone.